Multilayer stretch film

Abstract

Various embodiments of this disclosure provide multilayer stretch films and oriented stretch films obtained, for example, from stretching a multilayer stretch film. The multilayer stretch film includes a first layer containing a first polymer resin, a second layer containing a polymer material, and a core layer disposed between the first and second layers. The core layer contains graphene. The oriented stretch film has a thickness in the range of about 4 μm to about 10 μm.

Description

[Technical Field]

[0001] Claim of priority This application claims priority and benefits of U.S. Provisional Patent No. 63 / 530,253, filed on 1 August 2023, and U.S. Provisional Patent No. 63 / 544,627, filed on 17 October 2023, with the entire contents of each incorporated by reference.

[0002] This disclosure relates to multilayer stretch films used to wrap, unitize, or otherwise secure goods for easier transport or storage. More specifically, this disclosure relates to multilayer stretch films having a core layer containing graphene. This disclosure also relates to oriented stretch films obtained, for example, from stretching the multilayer stretch films disclosed herein. [Background technology]

[0003] Plastic stretch films are frequently used to tightly wrap or hold goods or assemblies of goods for transport or storage purposes. They can be single-layer or multi-layer films designed to stretch in response to applied force. For example, the metal industry often uses stretch films to unitize heavy goods or loads, such as feedstock for large rolls (e.g., steel or aluminum coils). These films are typically multi-layer films, and some of them can self-seal when overlapped. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Chinese Patent Application Publication No. 109177400 Specification [Patent Document 2] Chinese Patent Application Publication No. 112677599 Specification [Patent Document 3] International Publication No. WO 2007 / 129371

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] Various embodiments of the present disclosure provide a multilayer stretch film.

MEANS FOR SOLVING THE PROBLEMS

[0006] The multilayer stretch film has a core layer containing graphene. The multilayer stretch film of the present disclosure has a balanced desired physical properties (e.g., mechanical performance and barrier performance) compared to other laminated films.

[0007] In one embodiment, the multilayer stretch film includes a first layer containing a first polymer resin, a second layer containing a polymer material, and a core layer disposed between the first layer and the second layer. The core layer contains graphene.

[0008] In one embodiment, the multilayer stretch film includes at least one first layer, at least one second layer, and a core layer disposed between the at least one first layer and the at least one second layer. Each of the at least one first layer contains a first polymer resin. Each of the at least one second layer contains a polymer material. The core layer contains graphene. The multilayer stretch film has more than three layers in total.

[0009] In one embodiment, the multilayer stretch film includes a first layer having a first surface and a second surface opposite the first surface, and a second layer disposed on the first surface of the first layer. The first layer is a core layer containing graphene. The second layer is a slip layer containing a first polymer resin.

[0010] Various embodiments of the present disclosure also provide, for example, oriented stretch films obtained by stretching a multilayer stretch film disclosed herein. The oriented stretch films of the present disclosure maintain the desired physical properties of the multilayer stretch film (e.g., puncture resistance).

[0011] In one embodiment, the oriented stretch film includes a first layer containing a first polymer resin, a second layer containing a polymer material, and a core layer disposed between the first and second layers. The core layer contains graphene. The oriented stretch film has a thickness in the range of about 4 μm to about 10 μm. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic cross-sectional view of one exemplary embodiment of a multilayer stretch film according to the present disclosure. [Figure 2] This is a schematic cross-sectional view of another exemplary embodiment of a multilayer stretch film according to the present disclosure. [Figure 3] This is a schematic cross-sectional view of another exemplary embodiment of a multilayer stretch film according to the present disclosure. [Figure 4] This is a schematic diagram showing the water vapor transmission rates of multilayer stretch film A and each comparative film. [Modes for carrying out the invention]

[0013] In the drawings, the layer thickness is exaggerated for clarity. The drawings show variations of exemplary embodiments, but these drawings are not necessarily intended to be mutually exclusive. Rather, as can be seen from the context of the embodiments for carrying out the invention below, certain features shown and described in different drawings can be combined with other features from other drawings to result in various embodiments when the drawings and their descriptions are considered as a whole.

[0014] Various embodiments of this disclosure provide multilayer stretch films. As shown in the following examples, the multilayer stretch films described herein offer balanced and beneficial properties compared to other laminated films. Some of these properties include adhesion, puncture resistance, load-holding, and barrier performance. Thus, when used to wrap, unitize, or otherwise secure goods, the multilayer stretch films described herein can perform at least as well as, and often better than, other laminated films.

[0015] I. Multilayer stretch film Figure 1 is a schematic cross-sectional view of one exemplary embodiment of a part of the multilayer stretch film 100 according to the present disclosure. As shown, the multilayer stretch film 100 includes a first layer 110, a second layer 120, and a core layer 130 disposed between the first layer 110 and the second layer 120.

[0016] In this embodiment, the first layer 110 is a non-adherent layer (e.g., a slip layer), and the second layer 120 is an adhesive layer. As described herein, the “adhesion” property of a film is generally defined as its cohesive bonding strength, e.g., its ability to bond to itself. This adhesion property allows the film to form a seal when it is wrapped around an article or an assembly of articles. In particular, when the film is wrapped around an article, the first layer 110 of the film is located on the side of the film furthest from the article, and the second layer 120 of the film is located on the side of the film closest to the article, thereby securely fastening the article to facilitate transport or storage.

[0017] In various embodiments, the first layer 110 comprises a first polymer resin. In various embodiments, the first polymer resin is low-density polyethylene resin (LDPE), linear low-density polyethylene resin (LLDPE), or a combination thereof.

[0018] The first layer 110 is designed to provide a smooth surface to allow the film to be easily wrapped around an article. This "non-adherent" property of the first layer 110 also facilitates the opening of the film, if desired. Thus, in various embodiments, the first layer 110 has a coefficient of friction of less than 1. For example, the coefficient of friction is in the range of 0.3 to 0.9, for example, 0.3 to 0.8, or 0.3 to 0.7, or 0.3 to 0.6, or 0.3 to 0.5, or 0.3 to 0.4, or 0.4 to 0.9, or 0.4 to 0.8, or 0.4 to 0.7, or 0.4 to 0.6, or 0.4 to 0.5, or 0.5 to 0.9, or 0.5 to 0.8, or 0.5 to 0.7, or 0.5 to 0.6, or 0.6 to 0.9, or 0.6 to 0.8, or 0.6 to 0.7, or 0.7 to 0.9, or 0.7 to 0.8, or 0.8 to 0.9.

[0019] On the other hand, the second layer 120 contains a polymer material and is designed to provide a surface with more measurable adhesion in order to allow the film to adhere tightly to itself and to the article when wrapped around it. This "adhesion" property of the second layer 120 allows the film to provide good load retention and ensures that the film maintains its tightness to securely wrap or hold the article during storage or transport.

[0020] Therefore, in various embodiments, the polymer material of the second layer 120 is a plastomer. Adding a plastomer to the second layer 120 can give the film stronger adhesion. In various embodiments, the amount of plastomer is in the range of 95% to 100% by weight of the second layer 120, for example, 95% to 99% by weight, or 95% to 98% by weight, or 95% to 97% by weight, or 95% to 96% by weight, or 96% to 100% by weight, or 96% to 99% by weight, or 96% to 98% by weight, or 96% to 97% by weight, or 97% to 100% by weight, or 97% to 99% by weight, or 97% to 98% by weight, or 98% to 100% by weight, or 98% to 99% by weight, or 99% to 100% by weight. In various embodiments, the plastomer is at least one C3-C such as C4α-olefin, C6α-olefin, C8α-olefin (e.g., 1-octene), or C6α-metallocene. 10 This is a polyolefin plastomer containing ethylene copolymerized with α-olefin.

[0021] To improve the processability of the plastomer, the second layer 120 also includes a processing aid. In various embodiments, the amount of the processing aid in the second layer 120 is in the range of 0.1% to 2% by weight, for example, 0.1% to 1.8% by weight, or 0.1% to 1.5% by weight, or 0.1% to 1.2% by weight, or 0.1% to 1% by weight, or 0.5% to 2% by weight, or 0.5% to 1.8% by weight, or 0.5% to 1.5% by weight, or 0.5% to 1.2% by weight, or 0.5% to 1% by weight, or 0.8% to 2% by weight, or 0.8% to 1.8% by weight, or 0.8% to 1.5% by weight, or 0.8% to 1.2% by weight, or 0.8% to 1% by weight. In various embodiments, the processing aid is a fluoropolymer. In various other embodiments, the processing aid is a fluoropolymer mixed with polyethylene glycol, tetrafluoroethylene, or a combination thereof.

[0022] In various other embodiments, the polymer material of the second layer 120 is an elastomer. By incorporating an elastomer into the second layer 120, the film can be given softness or flexibility. In various embodiments, the amount of elastomer is in the range of 95% to 100% by weight of the second layer 120, for example, 95% to 99% by weight, or 95% to 98% by weight, or 95% to 97% by weight, or 95% to 96% by weight, or 96% to 100% by weight, or 96% to 99% by weight, or 96% to 98% by weight, or 96% to 97% by weight, or 97% to 100% by weight, or 97% to 99% by weight, or 97% to 98% by weight, or 98% to 100% by weight, or 98% to 99% by weight, or 99% to 100% by weight. In various embodiments, the elastomer is an ethylene-vinyl acetate (EVA) copolymer.

[0023] In various embodiments, to correct the tackiness of the film, the second layer 120 is C4~C 10 The system further includes polymers. In various embodiments, C4~C 10The polymer system is present in the second layer 120 in a range of 0.1% to 5.0% by weight, for example, 0.1% to 4.5% by weight, or 0.1% to 4.0% by weight, or 0.1% to 3.5% by weight, or 0.1% to 3.0% by weight, or 0.1% to 2.5% by weight, or 0.1% to 2.0% by weight, or 0.1% to 1.5% by weight, or 0.1% to 1.0% by weight, or 0.1% to 0.5% by weight, or 0.5% to 5.0% by weight, or 0.5% to 4.5% by weight, or 0.5% to 4.0% by weight. This is an amount in the range of weight %, or 0.5% to 3.5% by weight, or 0.5% to 3.0% by weight, or 0.5% to 2.5% by weight, or 0.5% to 2.0% by weight, or 0.5% to 1.5% by weight, or 1.0% to 5.0% by weight, or 1.0% to 4.5% by weight, or 1.0% to 4.0% by weight, or 1.0% to 3.5% by weight, or 1.0% to 3.0% by weight, or 1.0% to 2.5% by weight, or 1.0% to 2.0% by weight, or 1.0% to 1.5% by weight. In various embodiments, C4~C 10 The polymer in question is polyisobutylene (PIB) polymer.

[0024] In various embodiments, to protect the packaged article from corrosion (for example, if the article has a metal surface), the second layer 120 further comprises a volatile corrosion inhibitor (VCI). VCI is a chemical that vaporizes when the film comes into contact with a metal surface, thereby creating a protective atmosphere around the packaged article to protect the article from rust and corrosion during storage or transport. In various embodiments, the amount of VCI in the second layer 120 ranges from 0.5% to 2.0% by weight, for example, 0.5% to 1.8% by weight, or 0.5% to 1.5% by weight, or 0.5% to 1.2% by weight, or 0.5% to 1.0% by weight, or 0.5% to 0.8% by weight, or 0.8% to 2.0% by weight, or 0.8% to 1.5% by weight, or 0.8% to 1.2% by weight, or 0.8% by weight. This is an amount in the range of 1.0% by weight, or 1.0% to 2.0% by weight, or 1.0% to 1.8% by weight, or 1.0% to 1.5% by weight, or 1.0% to 1.2% by weight, or 1.2% to 2.0% by weight, or 1.2% to 1.8% by weight, or 1.2% to 1.5% by weight, or 1.5% to 2.0% by weight, or 1.5% to 1.8% by weight, or 1.8% to 2.0% by weight.Furthermore, in various embodiments, the VCI is in the range of 0.5% to 5.0% by weight of the second layer 120, for example, 0.5% to 4.5% by weight, or 0.5% to 4.0% by weight, or 0.5% to 3.5% by weight, or 0.5% to 3.0% by weight, or 0.5% to 2.5% by weight, or 0.5% to 2.0% by weight, or 0.5% to 1.5% by weight, and This ranges from 0.5% to 1.0% by weight, or 1.0% to 4.5% by weight, or 1.0% to 4.0% by weight, or 1.0% to 3.5% by weight, or 1.0% to 3.0% by weight, or 1.0% to 2.5% by weight, or 1.0% to 2.0% by weight, or 1.0% to 1.5% by weight, or 1.5% to 4.5% by weight, or 1.5% to 4.0% by weight. %, or 1.5% to 3.5% by weight, or 1.5% to 3.0% by weight, or 1.5% to 2.5% by weight, or 1.5% to 2.0% by weight, or 2.0% to 4.5% by weight, or 2.0% to 4.0% by weight, or 2.0% to 3.5% by weight, or 2.0% to 3.0% by weight, or 2.0% to 2.5% by weight, or 2.5% to 4% by weight It is a quantity in the range of 0.5% by weight, or 2.5% to 4.0% by weight, or 2.5% to 3.5% by weight, or 2.5% to 3.0% by weight, or 3.0% to 4.5% by weight, or 3.0% to 4.0% by weight, or 3.0% to 3.5% by weight, or 3.5% to 4.5% by weight, or 3.5% to 4.0% by weight, or 4.0% to 4.5% by weight.

[0025] The first layer 110 is a non-adherent layer, but may still exhibit a small amount of measurable adhesion. However, the adhesion characteristics exhibited by the first layer 110 are generally weaker than those exhibited by the second layer 120. Therefore, the adhesion force exhibited between two adherent layers of adjacent film structures, as disclosed herein, is generally stronger than the adhesion force exhibited between the adherent layer of one film and the non-adherent layer of the other film.

[0026] Therefore, in various embodiments, the multilayer stretch film 100 exhibits an adhesion strength of at least 200 grams-weight / inch, for example, at least 205 grams-weight / inch, or at least 210 grams-weight / inch, or at least 215 grams-weight / inch, or at least 220 grams-weight / inch, as measured by ASTM D5458.

[0027] Furthermore, in various embodiments, the multilayer stretch film 100 has a weight range of 5 to 100 grams-weight / inch when measured according to ASTM D882 and ASTM D5458, for example, 5 to 80 grams-weight / inch, or 5 to 60 grams-weight / inch, or 5 to 40 grams-weight / inch, or 5 to 20 grams-weight / inch, or 5 to 10 grams-weight / inch, or 10 to 100 grams-weight / inch, or 10 to 80 grams-weight / inch, or 10 to 60 grams-weight / inch, or 10 to 40 grams-weight / inch, or 10 to 20 grams-weight / inch, and This indicates adhesion between the second layer 120 and the first layer 110 in the range of 20 to 100 grams-force / inch, or 20 to 80 grams-force / inch, or 20 to 60 grams-force / inch, or 20 to 40 grams-force / inch, or 40 to 100 grams-force / inch, or 40 to 80 grams-force / inch, or 40 to 60 grams-force / inch, or 60 to 100 grams-force / inch, or 60 to 80 grams-force / inch, or 80 to 100 grams-force / inch.

[0028] Referring to Figure 1, the multilayer stretch film 100 includes a core layer 130 positioned between a first layer 110 and a second layer 120. As disclosed herein, the inventors have determined that by incorporating graphene into the core layer 130, the overall strength and durability of the film can be significantly improved without interfering with the film's adhesion and non-adhesion properties. For example, the inventors have determined that by incorporating graphene into the core layer 130, the puncture resistance, barrier performance, and structural integrity of the film can be enhanced.

[0029] As used herein, the term "graphene" refers to pure graphene or graphene derivatives. Specifically, pure graphene is sp 2 Graphene is a two-dimensional (2D) atomic crystal consisting of a single-atom-layer (i.e., monolayer) honeycomb structure of carbon atoms bonded together. Graphene derivatives can be functionalized graphene, graphene oxide, or reduced graphene oxide. For example, functionalized graphene refers to pure graphene with various chemical functional groups (e.g., -OH, -COOH, or NH2) incorporated into the graphene lattice. Graphene oxide, also known as graphite oxide or graphitic acid, refers to compounds of varying ratios of carbon, oxygen, and hydrogen obtained by treating graphite with strong oxidizing agents and / or strong acids. Reduced graphene oxide refers to graphene oxide that has been treated to reduce its oxygen content.

[0030] Therefore, in various embodiments, the core layer 130 contains graphene in an amount ranging from 0.5% to 10% by weight, for example, 0.5% to 9% by weight, or 0.5% to 8% by weight, or 0.5% to 7% by weight, or 0.5% to 6% by weight, or 0.5% to 5% by weight, or 0.5% to 4% by weight, or 0.5% to 3% by weight, or 0.5% to 2% by weight, or 0.5% to 1% by weight, or 1% to 10% by weight, or 1% to 9% by weight, or 1% to 8% by weight, or 1% to 7% by weight, or 1% to 6% by weight, or 1% to 5% by weight, or 1% to 4% by weight, or 1% to 3% by weight, or 1% to 2% by weight.

[0031] In various other preferred embodiments, the core layer 130 comprises a plurality of separate layers, each of which contains graphene as described herein. For example, each layer contains graphene in an amount ranging from 0.5% to 10% by weight.

[0032] The core layer 130 further comprises a second polymer resin. In various embodiments, the amount of the second polymer resin is in the range of 90% to 99.5% by weight of the core layer 130, for example, 90% to 99% by weight, or 90% to 98% by weight, or 90% to 97% by weight, or 90% to 96% by weight, or 90% to 95% by weight, or 90% to 94% by weight, or 90% to 93% by weight, or 90% to 92% by weight, or 90% to 91% by weight. In various embodiments, the second polymer resin is linear low-density polyethylene resin (LLDPE).

[0033] The total thickness of the multilayer stretch film 100 may vary depending on the specific application of the film. In various embodiments, the total thickness of the multilayer stretch film 100 is 20 μm. In other various embodiments, the total thickness of the multilayer stretch film 100 is 30 μm. In other various embodiments, the total thickness of the multilayer stretch film 100 is 50 μm. In other various embodiments, the total thickness of the multilayer stretch film 100 is 60 μm. In other various embodiments, the total thickness of the multilayer stretch film 100 is 80 μm.

[0034] In various embodiments, the core layer 130 has a thickness of at least 70% of the total thickness of the multilayer stretch film 100, for example, at least 75%, at least 80%, at least 85%, at least 90%, or at least 95%.

[0035] As described above, the multilayer stretch film 100 can be stretched in response to an applied force. Therefore, in various embodiments, the multilayer stretch film 100 can be stretched to more than 50% of its original unstretched length, for example, more than 80%, or more than 100%, or more than 120%, or more than 150%, or more than 200%, as measured by ASTM D4649.

[0036] In various embodiments, the multilayer stretch film 100 has a longitudinal (MD) tear strength of at least 700 g, for example, at least 750 g, or at least 800 g, as measured by ASTM D1922. In various embodiments, the multilayer stretch film 100 also has a tear direction (TD) tear strength of at least 1000 g, for example, at least 1100 g, or at least 1200 g, as measured by ASTM D1922.

[0037] In various embodiments, the multilayer stretch film 100 exhibits an impact resistance of at least 450 g, for example, at least 500 g, or at least 550 g, as measured by ASTM D1709.

[0038] In various embodiments, the multilayer stretch film 100 exhibits a puncture resistance of more than 6N, for example, more than 7N, or more than 8N, or more than 10N, as measured by ASTM F1306.

[0039] In various embodiments, the first layer 110 of the multilayer stretch film 100 has a surface energy in the range of 25 mN / m to 30 mN / m, for example, 25 mN / m to 28 mN / m, or 26 mN / m to 30 mN / m, or 26 mN / m to 28 mN / m, or 28 mN / m to 30 mN / m, when measured by a Kruss Scientific mobile surface analyzer. In various embodiments, the second layer 120 of the multilayer stretch film 100 has a surface energy in the range of 25 mN / m to 30 nM / m, for example, 25 mN / m to 28 mN / m, or 26 mN / m to 30 mN / m, or 26 mN / m to 28 mN / m, or 28 mN / m to 30 mN / m, when measured by a Kruss Scientific mobile surface analyzer.

[0040] In various embodiments, the multilayer stretch film 100 has a water vapor transmission rate of 60 g / m² when measured by an Ametek Mocon WVTR water vapor transmission analyzer. 2 / day to 140 g / m 2 / day range, for example, 60 g / m 2 / day to 120 g / m 2 / day, or 60 g / m 2 / day to 100 g / m 2 / day, or 60 g / m 2 / day to 80 g / m 2 / day, or 80 g / m 2 / day to 140 g / m 2 / day, or 80 g / m 2 / day to 120 g / m 2 / day, or 80 g / m 2 / day to 100 g / m 2 / day, or 100 g / m 2 / day to 140 g / m 2 / day, or 100 g / m 2 / day to 120 g / m 2 / day, or 120 g / m 2 / day to 140 g / m 2 / day range of water vapor transmission rate.

[0041] In various embodiments, the multilayer stretch film 100 has a maximum surface resistivity of 5.20×10 measured by ASTM D257-14. 15 Ω / square, for example, a maximum of 5.00×10 15 Ω / square.

[0042] In various embodiments, the multilayer stretch film 100 has a volume resistivity in the range of 1.0×10 17 Ω·cm to 2.0×10 17 Ω·cm, for example, 1.2×10 17 Ω·cm to 2.0×10 17 Ω·cm, or 1.4×10 17 Ω·cm to 2.0×10 17 Ω·cm, or 1.6×10 17 Ω·cm to 2.0×10 17 Ω·cm, or 1.8×10 17 Ω·cm to 2.0×10 17 Ω·cm.

[0043] To modify the adhesion and / or non-adhesion properties of the film, the multilayer stretch film described herein may include two or more separate adhesion and / or non-adhesion layers, which are arranged on the upper and lower two surfaces of the core layer. Figure 2 is a schematic cross-sectional view of a portion of such embodiments of the multilayer stretch film 200 according to this disclosure. As shown, the multilayer stretch film 200 includes at least one first layer 210, at least one second layer 220, and a core layer 230 disposed between at least one first layer 210 and at least one second layer 220. As described herein, at least one first layer 210 is a non-adhesion layer, and at least one second layer 220 is an adhesion layer. Furthermore, the core layer 230 includes graphene as disclosed herein. In this embodiment, the multilayer stretch film 200 has a total of more than three layers, for example, a total of four layers, or a total of five layers, or a total of six layers, or a total of seven layers.

[0044] Figure 3 is a schematic cross-sectional view of another exemplary embodiment of a part of the multilayer stretch film 300 according to the present disclosure. As shown, the multilayer stretch film 300 includes a first layer 310 having a first surface 312 and a second surface 314 opposite the first surface 312. The first layer 310 is a core layer containing graphene. The multilayer stretch film 300 also includes a second layer 320 disposed on the first surface 312 of the first layer 310. As disclosed herein, the second layer 320 is a non-adhesion layer. In this embodiment, the multilayer stretch film 300 does not include an adhesion layer as described above. The multilayer stretch film 300 can exhibit antistatic properties (e.g., preventing the accumulation of ions and electronic charges). The multilayer stretch film 300 can be used to wrap electronic devices.

[0045] The multilayer stretch films of this disclosure can be manufactured by any film lamination and / or co-extrusion technique, and using any inflated or cast film extrusion and lamination apparatus known in the art.

[0046] The multilayer stretch films disclosed herein can be stretched in the factory before being delivered to the end user. Thus, the stretched film is a film that is removed from a roll of already manufactured film, stretched in another process or in-line process, and then wound back onto a film roll for later use. Such stretching before delivery to the end user as described herein is different from stretching the multilayer stretch film at the time of use by the end user.

[0047] Stretching allows for longer film lengths, which not only increases the proportion of packages that can be wrapped but also reduces packaging costs by eliminating potential waste from unstretched film. In various embodiments, the stretched multilayer stretch film has a stretch ratio in the range of about 1:1.5 to about 1:4, for example, about 1:1.5 to about 1:3.5, or about 1:1.5 to about 1:3, or about 1:1.5 to about 1:2.5, or about 1:1.5 to about 1:2, or about 1:2 to about 1:4, or about 1:2 to about 1:3.5, or about 1:2 to about 1:3, or about 1:2 to about 1:2.5, or about 1:2.5 to about 1:4, or about 1:2.5 to about 1:3.5, or about 1:2.5 to about 1:3, or about 1:2.5 to about 1:3, or about 1:3 to about 1:4, or about 1:3 to about 1:3.5, or about 1:3.5 to about 1:4. In some embodiments, the stretched multilayer stretch films described herein have a stretch ratio of about 1:2, or about 1:2.5, or about 1:3, or about 1:3.5. As used herein, the term “stretch ratio” means the ratio of the total length of the film before stretching to the total length of the film after stretching. For example, a stretch ratio of 1:2 means that the multilayer stretch film is stretched to 200% of the total length of the film before stretching.

[0048] As described above, the multilayer stretch films disclosed herein include various polyethylenes. Stretching can orient molecules in the film along the stretching direction (e.g., longitudinal or tearing direction). Thus, in some embodiments, the stretched film is also an oriented stretch film. In some embodiments, stretching is performed in two directions (e.g., two orthogonal directions) to form a biaxially oriented stretch film. In some embodiments, stretching is performed in only one direction to form a mono-oriented or uniaxially oriented stretch film. Stretched films are relatively rigid for their thickness and have little residual orientation or stretch remaining before the film breaks in the stretching direction (e.g., ruptures). These properties are desirable because they require far less effort from the end user to wrap or secure packages using these stretch films compared to conventional handheld stretch films. In various embodiments, an unoriented stretch film is converted into an oriented stretch film by stretching the stretch film to about 150% to about 400% of the original film length to achieve the desired thickness.

[0049] Furthermore, as a result of stretching, the gauge of the stretched film is thinner compared to the unstretched film. Often, thinner films are more susceptible to the introduction of surface defects and / or fractures. However, the inventors have unexpectedly found that by incorporating a graphene-containing core layer between the non-adherent and adherent layers, the multilayer stretch films disclosed herein can be stretched to have a thin thickness while maintaining the physical properties (e.g., mechanical properties) of the film, and that stretching does not impair the adhesion and non-adherence properties of the film. Thus, the oriented films described herein can perform the same functions as other oriented films while using less film material, thereby reducing the cost of the oriented film.

[0050] In various embodiments, the stretched film has a thickness in the range of about 20% to about 50% of the total thickness of the multilayer stretch film before stretching, for example, about 25%, about 30%, about 35%, about 40%, or about 45% of the total thickness of the multilayer stretch film before stretching. In various embodiments, the total thickness of the multilayer stretch film is in the range of about 14 μm to about 50 μm. In various embodiments, the stretched film has a thickness in the range of about 4 μm to about 10 μm.

[0051] In various embodiments, the stretched film exhibits an adhesion strength of at least 200 grams-force / inch, for example, at least 250 grams-force / inch, or at least 300 grams-force / inch, or at least 350 grams-force / inch, as measured by ASTM D5458.

[0052] In various embodiments, the stretched film exhibits adhesion between the adhesive and non-adherent layers in the range of 50 to 100 grams-force / inch, for example, 60 to 100 grams-force / inch, or 70 to 100 grams-force / inch, or 80 to 100 grams-force / inch, or 60 to 80 grams-force / inch, or 70 to 80 grams-force / inch, as measured by ASTM D5458.

[0053] Therefore, by incorporating a graphene-containing core layer between the non-adhesion and adhesion layers, the multilayer stretch films disclosed herein provide a balanced set of desirable properties. In particular, the inventors have determined that by including graphene in the core layer, the mechanical strength and barrier performance of the film can be significantly improved without interfering with the adhesion and non-adhesion properties of the outer layers of the film, resulting in a film that provides excellent physical protection to the articles thus packaged. In addition, the "non-adhesion" properties of the film allow for easy application, and the adhesion layer ensures excellent load retention. Furthermore, the inventors have determined that the presence of graphene in the core layer makes it possible to stretch the film into a thin film while maintaining the physical properties of the multilayer stretch film. This configuration of the film structure makes the film suitable for a wide range of applications in various industries.

[0054] II. Examples Tests were conducted using exemplary multilayer stretch films disclosed herein. Table 1 lists two such multilayer stretch films, namely Film A and Film B. In particular, Film A contains 1% graphene in its core layer, and Film B contains 5% graphene in its core layer. Both films have a total thickness of 50 μm, and the thickness of the core layer of each film is 38.5 μm.

[0055] [Table 1]

[0056] 1.Puncture resistance a. Multilayer stretch film A puncture resistance test measures a material's ability to withstand being fractured by a probe when a force is applied to it at a constant rate. Accordingly, the inventors tested film A in accordance with ASTM F1306 to evaluate the puncture resistance of the multilayer stretch film disclosed herein. For comparison, the inventors also tested two comparative laminated films, film C1 and film C2, under similar conditions. Film C1 is a commercially available film from PanaceaWrap containing a mixture of polyethylene terephthalate (PET), LDPE, and LLDPE. Film C2 is a commercially available film from MetPro containing LDPE. In particular, neither film C1 nor film C2 contains graphene in their composition. The following data were obtained.

[0057] [Table 2]

[0058] [Table 3]

[0059] Table 2 shows that film A requires a force of at least 6 N to break, as measured by ASTM F1306. Table 2 also shows that the force required to break film A increases with increasing crosshead velocity. These are consistent with the data obtained for films C1 and C2. Therefore, although not intended to be theoretical, Table 2 suggests that the puncture resistance of film A is at least comparable to that of films C1 and C2.

[0060] Furthermore, Table 3 shows that film A exhibits a higher compressive displacement than films C1 and C2. This indicates that, in order to break film A, the probe needs to penetrate film A over a longer distance than it does through films C1 and C2.

[0061] In summary, the data suggests that the presence of graphene in its core layer gives film A a puncture resistance comparable to that of films C1 and C2.

[0062] b. Oriented stretch film To evaluate the puncture resistance of stretched multilayer films as disclosed herein, the inventors performed a puncture resistance test on film P1 in accordance with ASTM F1306. Film P1 contains graphene and has a thickness of 5.2 μm. As used herein, film P1 is stretched film A as described in Section II.1.a. Film P1 is a different specimen from film A tested in Section II.1.a. For comparison, the inventors also tested a comparative laminated film ("film C7") under similar conditions. Film C7 is a commercially available film from Signode that does not contain graphene in its composition and has a thickness of 6.6 μm. The following data were obtained at a crosshead speed of 50 mm / min.

[0063] [Table 4]

[0064] Table 7 shows that film P1 can withstand forces exceeding 4N, which is greater than the force required to break film C7. This observation indicates that film P1 has higher puncture resistance than film C3. The data also shows that film P1 exhibits higher compressive displacement than film C7, suggesting that the probe needs to penetrate film P1 over a longer distance than it does film C7 to break it.

[0065] Therefore, although not intended to be theoretically binding, Table 7 shows that the presence of graphene in its core layer helps the stretched film maintain its mechanical strength, making the film more resistant to punctures than a graphene-free film.

[0066] 2. Water vapor transmission rate Water vapor transmission rate (WVTR) is the amount of water vapor per square meter (g / m²) per 24 hours. 2 Measured in 1 / day, this is considered to indicate the permeability of the material (i.e., the material's ability to permeate water vapor). Therefore, the inventors evaluated the WVTR of film A using an Ametek Mocon water vapor permeability analyzer. For comparison, the inventors also measured the WVTR of other comparative films, including films C3, C4, C5, and C6, using an Ametek Mocon water vapor permeability analyzer. In particular, both films C3 and C4 are multilayer stretch films similar to film A, but unlike film A, neither film C3 nor film C4 contains graphene in its core layer, and both films C3 and C4 contain elastomer, PIB polymer, and VCI in their adhesion layers. Film C5 is a commercially available film from Cleveland Cliffs, and its composition contains PET but not graphene. Film C6 is a multilayer stretch film similar to film A, but unlike film A, film C6 does not contain graphene in its core layer. Table 4 lists the respective thicknesses of film A and its comparison films for WVTR measurement.

[0067] [Table 5]

[0068] Figure 4 is a schematic diagram showing the water vapor transmission rates measured for film A and each comparative film. As shown in Figure 4, film A has a transmission rate of 60 g / m². 2 / day~140g / m 2It exhibits a water vapor transmission rate in the range of / day, which is much lower than the water vapor transmission rate measured for film C6 (i.e., film A without graphene). Similar results were observed for films C3 and C4, both showing higher WVTRs than film A. Figure 4 also shows that the WVTR of film A is similar to that of film C5.

[0069] Therefore, although not intended to be theoretically bound, the data shows that the presence of graphene in film A can prevent water vapor from passing through the film. This gives film A enhanced barrier performance compared to films C6, C3, and C4, with the barrier performance of film A being at least comparable to that of film C5.

[0070] In summary, the data suggests that the presence of graphene in its core layer gives film A enhanced barrier performance compared to film A without graphene (i.e., film C6), as well as films C3 and C4, and that the barrier performance of film A is at least comparable to that of film C5.

[0071] 3. Surface / Volume Resistivity Surface resistivity is the resistance to leakage current along the surface of an insulating material. Volume resistivity is the resistance to leakage current passing through the body of the insulating material. The higher the surface / volume resistivity, the lower the leakage current and the lower the conductivity of the material. Accordingly, the inventors tested film B in accordance with ASTM D257-14 to evaluate the surface / volume resistivity of the multilayer stretch film disclosed herein. For comparison, the inventors also tested a commercially available antistatic bag ("control"). The antistatic bag did not contain graphene. The following data were obtained.

[0072] [Table 6]

[0073] [Table 7]

[0074] Table 5 shows that the surface resistivity of film B is a maximum of 5.20 × 10⁻⁶. 15 It is Ω / square and appears to be the same as the symmetrical model. Furthermore, Table 6 shows that film B is 1.2 × 10 17 Ω·cm ~ 1.6 × 10 17 The film exhibits a volume resistivity in the range of Ω·cm, which is significantly higher than the control. Therefore, while not intended to be theoretically bound, the data suggest that incorporating graphene into a multilayer stretch film can provide a film with surface / volume resistivity at least comparable to commercially available antistatic bags.

[0075] 4. Adhesion characteristics To evaluate the adhesion properties of the stretched multilayer stretch film disclosed herein, the inventors measured both I / O and O / O adhesion forces of film P2 in accordance with ASTM D5458. Where herein, “adhesion force I / O” refers to the adhesion force between the adhesive and non-adhesion layers of film P2, and “adhesion force O / O” refers to the adhesion force between the adhesive layers of film P2. Film P2 is a stretched film containing graphene, obtained by stretching film A as described in Section II.1.a. Film P2 is a different specimen from film A tested in Section II.1.a. Where herein, film A has a total thickness of 17 μm and a total film length of 4500 m before stretching. For comparison, the inventors also measured the adhesion force of a comparative laminated film ("film C8"). Film C8 is a commercially available film from Signode, which does not contain graphene in its composition and has a total thickness of 6.82 μm. The following data were obtained.

[0076] [Table 8]

[0077] As shown in Table 8, film P2 is a stretched film obtained by stretching film A to 250%, 280%, or 290% of the total length of film A, with the resulting film P2 having thicknesses of 6.90 μm, 5.58 μm, or 5.10 μm, respectively. In particular, when film A is stretched to film P2 with a thickness of 6.90 μm, the resulting film P2 has an adhesion force I / O of approximately 83.7 gram-force / inch and an adhesion force O / O of approximately 280 gram-force / inch, as measured by ASTM D5458, suggesting that film P2 exhibits better adhesion and non-adhesion properties than film C8. Similar results can be seen when film A is stretched to film P2 with thicknesses of 5.58 and 5.10 μm, which are 280% and 290% of its total length, respectively.

[0078] Therefore, although not intended to be constrained by theory, these data suggest that even when the film is stretched, the presence of graphene in the core layer does not impede the film's adhesion and non-adhesion properties.

[0079] III. Conclusion Accordingly, in various embodiments, the present disclosure provides multilayer stretch films. The multilayer stretch film comprises a first layer containing a first polymer resin, a second layer containing a polymer material, and a core layer disposed between the first and second layers. The core layer contains graphene.

[0080] In various such embodiments of the multilayer stretch film, the first polymer resin is a low-density polyethylene resin.

[0081] In various such embodiments of the multilayer stretch film, the first polymer resin is a linear low-density polyethylene resin.

[0082] In various such embodiments of the multilayer stretch film, the first layer is a slip layer having a coefficient of friction in the range of 0.3 to 0.9.

[0083] In various such embodiments of multilayer stretch films, the polymer material of the second layer is a plastomer.

[0084] In various such embodiments of multilayer stretch films, the plastomer has at least one C3-C 10 This is a polyolefin plastomer containing ethylene copolymerized with α-olefin.

[0085] In various such embodiments of multilayer stretch films, at least one C3~C 10 α-olefins are C4α-olefins, C6α-olefins, C8α-olefins, or C6α-metallocenes.

[0086] In various such embodiments of the multilayer stretch film, the plastomer is in an amount ranging from 95% to 100% by weight of the second layer.

[0087] In various such embodiments of the multilayer stretch film, the second layer further comprises a processing aid.

[0088] In various such embodiments of multilayer stretch films, the processing aid is a fluoropolymer.

[0089] In various such embodiments of multilayer stretch films, the processing aid is a fluoropolymer mixed with polyethylene glycol, tetrafluoroethylene, or a combination thereof.

[0090] In various such embodiments of multilayer stretch films, the processing aid is present in an amount ranging from 0.1% to 2% by weight of the second layer.

[0091] In various such embodiments of the multilayer stretch film, the processing aid is in an amount ranging from 0.5% to 1.5% by weight of the second layer.

[0092] In various such embodiments of multilayer stretch films, the processing aid is present in an amount ranging from 0.8% to 1.2% by weight of the second layer.

[0093] In various such embodiments of multilayer stretch films, the polymer material of the second layer is an elastomer.

[0094] In various such embodiments of multilayer stretch films, the elastomer is an ethylene-vinyl acetate (EVA) copolymer.

[0095] In various such embodiments of the multilayer stretch film, the amount of elastomer is in the range of 95% to 100% by weight of the second layer.

[0096] In various such embodiments of multilayer stretch films, the second layer is C4~C 10 It further contains polymers.

[0097] In various such embodiments of multilayer stretch films, C4~C 10 The polymer in question is polyisobutylene (PIB) polymer.

[0098] In various such embodiments of multilayer stretch films, C4~C 10 The amount of the polymer system is in the range of 0.1% to 5% by weight in the second layer.

[0099] In various such embodiments of the multilayer stretch film, the second layer further comprises a volatile corrosion inhibitor (VCI).

[0100] In various such embodiments of the multilayer stretch film, the amount of VCI is in the range of 0.5% to 2.0% by weight of the second layer.

[0101] In various such embodiments of the multilayer stretch film, the amount of VCI is in the range of 0.5% to 5.0% by weight of the second layer.

[0102] In various such embodiments of multilayer stretch films, the multilayer stretch film has an adhesion strength of at least 200 grams-force / inch, as measured by ASTM D5458.

[0103] In various such embodiments of multilayer stretch films, the multilayer stretch film has an adhesion between the second layer and the first layer, ranging from 5 to 100 grams-force / inch, as measured by ASTM D5458.

[0104] In various such embodiments of multilayer stretch films, the amount of graphene is in the range of 0.5% to 10% by weight of the core layer.

[0105] In various such embodiments of multilayer stretch films, graphene is present in an amount ranging from 1% to 10% by weight in the core layer.

[0106] In various such embodiments of multilayer stretch films, graphene is present in an amount ranging from 1% to 5% by weight in the core layer.

[0107] In various such embodiments of the multilayer stretch film, the core layer comprises a plurality of separate layers, each of which contains graphene in an amount ranging from 0.5% to 10% by weight.

[0108] In various such embodiments of the multilayer stretch film, the core layer further comprises a second polymer resin.

[0109] In various such embodiments of the multilayer stretch film, the second polymer resin is a linear low-density polyethylene resin.

[0110] In various such embodiments of the multilayer stretch film, the core layer has a thickness of at least 70% of the total thickness of the multilayer stretch film.

[0111] In various such embodiments of multilayer stretch films, the multilayer stretch film has a longitudinal tear strength of at least 700 g, as measured by ASTM D1922.

[0112] In various such embodiments of multilayer stretch films, the multilayer stretch film has a tear strength in the tear direction of at least 1000 g, as measured by ASTM D1922.

[0113] In various such embodiments of multilayer stretch films, the multilayer stretch film has an impact resistance of at least 450 g, as measured by ASTM D1709.

[0114] In various such embodiments of multilayer stretch films, the multilayer stretch film has a puncture resistance greater than 6N when measured according to ASTM F1306.

[0115] In various such embodiments of the multilayer stretch film, the first layer has a surface energy in the range of 25 mN / m to 30 mN / m.

[0116] In various such embodiments of the multilayer stretch film, the second layer has a surface energy in the range of 25 mN / m to 30 mN / m.

[0117] In various such embodiments of multilayer stretch film, the multilayer stretch film has a density of 60 g / m². 2 / day~140g / m 2 It has a water vapor transmission rate in the range of / day.

[0118] In various such embodiments of multilayer stretch film, the multilayer stretch film has a maximum size of 5.20 × 10 when measured according to ASTM D257-14. 15 It has a surface resistivity of Ω / square.

[0119] In various such embodiments of multilayer stretch film, the multilayer stretch film has dimensions of 1.0 × 10⁻¹ when measured according to ASTM D257-14. 17 Ω·cm~2.0×10 17 It has a volume resistivity in the range of Ω·cm.

[0120] In various other embodiments, the Disclosure further provides multilayer stretch films. A multilayer stretch film comprises at least one first layer, at least one second layer, and a core layer disposed between the at least one first layer and the at least one second layer. Each of the at least one first layer comprises a first polymer resin. Each of the at least one second layer comprises a polymer material. The core layer comprises graphene. A multilayer stretch film has a total of more than three layers.

[0121] In various such embodiments of multilayer stretch film, the total number of layers of the multilayer stretch film is 4 to 7.

[0122] In various such embodiments of multilayer stretch films, the amount of graphene is in the range of 0.5% to 10% by weight of the core layer.

[0123] In various such embodiments of the multilayer stretch film, the core layer comprises a plurality of separate layers, each of which contains graphene in an amount ranging from 0.5% to 10% by weight.

[0124] In various other embodiments, the Disclosure further provides multilayer stretch films. A multilayer stretch film includes a first layer having a first surface and a second surface opposite the first surface, and a second layer disposed on the first surface of the first layer. The first layer is a core layer comprising graphene. The second layer is a slip layer comprising a first polymer resin.

[0125] In various such embodiments of the multilayer stretch film, the amount of graphene in the first layer ranges from 0.5% to 10% by weight.

[0126] Furthermore, in various embodiments, the Disclosure provides an oriented stretch film. The oriented stretch film comprises a first layer containing a first polymer resin, a second layer containing a polymer material, and a core layer disposed between the first and second layers. The core layer contains graphene. The oriented stretch film has a thickness ranging from about 4 μm to about 10 μm. In various such embodiments of the oriented stretch film, the oriented stretch film is a stretched film obtained by stretching a multilayer stretch film disclosed herein to orient the molecules in the film along the stretching direction.

[0127] In various such embodiments of oriented stretch films, the total thickness of the multilayer stretch film is in the range of about 14 μm to about 50 μm.

[0128] In various such embodiments of the oriented stretch film, the first polymer resin in the first layer of the oriented stretch film is a low-density polyethylene resin or a linear low-density polyethylene resin.

[0129] In various such embodiments of the oriented stretch film, the polymer material in the second layer of the oriented stretch film is a plastomer disclosed herein.

[0130] In various such embodiments of the oriented stretch film, the amount of graphene in the core layer of the oriented stretch film is in the range of 0.5% to 10% by weight of the core layer.

[0131] In various such embodiments of oriented stretch films, the oriented stretch film has a stretch ratio in the range of about 1:1.5 to about 1:4.

[0132] In various such embodiments of the oriented stretch film, the oriented stretch film has a stretch ratio in the range of about 1:1.5 to about 1:3.

[0133] In various such embodiments of the oriented stretch film, the oriented stretch film has a stretch ratio of about 1:2.

[0134] In various such embodiments of the oriented stretch film, the oriented stretch film has a stretch ratio of about 1:2.5.

[0135] In various such embodiments of the oriented stretch film, the oriented stretch film has a stretch ratio of about 1:3.

[0136] In various such embodiments of orientation stretch films, the orientation stretch film is a biaxially orientation stretch film.

[0137] In various such embodiments of orientation stretch films, the orientation stretch film is a mono-oriented or uniaxially oriented stretch film.

[0138] In various such embodiments of the oriented stretch film, the oriented stretch film has an adhesion strength of at least 250 grams-force / inch, as measured by ASTM D5458.

[0139] In various such embodiments of the oriented stretch film, the oriented stretch film has an adhesion between the second layer and the first layer in the range of 50 to 100 grams-force / inch, as measured by ASTM D5458.

[0140] Various changes and modifications to the embodiments described herein will be obvious to those skilled in the art. These changes and modifications can be made without departing from the spirit and scope of this subject matter and without impairing the intended advantages. Not all illustrated components described herein are required, and some implementations can include different or fewer components in addition to those expressly described herein. Changes to the arrangement and type of components, the shape, size, and material of components, and the manner of mounting and connection of components can be made without departing from the spirit or scope of the claims described herein. Furthermore, unless otherwise indicated, any directions referred to herein reflect the orientation of components shown in the corresponding drawings and do not limit the scope of this disclosure. This specification is intended to be taken as a whole and interpreted in accordance with the principles of the invention taught herein and understood by those skilled in the art.

Claims

1. A first layer containing a first polymer resin, A second layer containing polymer material, A core layer disposed between the first layer and the second layer, wherein the core layer includes graphene, and A multilayer stretch film including [this].

2. The multilayer stretch film according to claim 1, wherein the first polymer resin is a low-density polyethylene resin.

3. The multilayer stretch film according to claim 1, wherein the first polymer resin is a linear low-density polyethylene resin.

4. The multilayer stretch film according to any one of claims 1 to 3, wherein the first layer is a slip layer having a coefficient of friction in the range of 0.3 to 0.

9.

5. The multilayer stretch film according to any one of claims 1 to 4, wherein the polymer material of the second layer is a plastomer.

6. The aforementioned plastomer has at least one C 3 ~C 10 The multilayer stretch film according to claim 5, which is a polyolefin plastomer containing ethylene copolymerized with α-olefin.

7. The at least one C 3 ~C 10 α-olefins, C 4 α-olefin, C 6 α-olefin, C 8 α-olefin, or C 6 The multilayer stretch film according to claim 6, wherein the film is α-metallocene.

8. The multilayer stretch film according to any one of claims 5 to 7, wherein the amount of the plastomer is in the range of 95% to 100% by weight of the second layer.

9. The multilayer stretch film according to any one of claims 5 to 8, wherein the second layer further comprises a processing aid.

10. The multilayer stretch film according to claim 9, wherein the processing aid is a fluoropolymer.

11. The multilayer stretch film according to claim 9, wherein the processing aid is a fluoropolymer mixed with polyethylene glycol, tetrafluoroethylene, or a combination thereof.

12. The multilayer stretch film according to any one of claims 9 to 11, wherein the processing aid is in an amount ranging from 0.1% to 2% by weight of the second layer.

13. The multilayer stretch film according to any one of claims 9 to 11, wherein the processing aid is in an amount ranging from 0.5% to 1.5% by weight of the second layer.

14. The multilayer stretch film according to any one of claims 9 to 11, wherein the processing aid is in an amount ranging from 0.8% to 1.2% by weight of the second layer.

15. The multilayer stretch film according to any one of claims 1 to 4, wherein the polymer material of the second layer is an elastomer.

16. The multilayer stretch film according to claim 15, wherein the elastomer is an ethylene-vinyl acetate (EVA) copolymer.

17. The multilayer stretch film according to claim 15 or claim 16, wherein the amount of the elastomer is in the range of 95% to 100% by weight of the second layer.

18. The second layer is C 4 to C 10 The multilayer stretch film according to any one of claims 1 to 17, further comprising a C

19. Said C 4 ~C 10 The multilayer stretch film according to claim 18, wherein the polymer system is a polyisobutylene (PIB) polymer.

20. Said C 4 ~C 10 The multilayer stretch film according to claim 18 or 19, wherein the polymer system is present in an amount ranging from 0.1% to 5% by weight of the second layer.

21. The multilayer stretch film according to any one of claims 1 to 20, wherein the second layer further comprises a volatile corrosion inhibitor (VCI).

22. The multilayer stretch film according to claim 21, wherein the amount of VCI is in the range of 0.5% to 2.0% by weight of the second layer.

23. The multilayer stretch film according to claim 21, wherein the amount of VCI is in the range of 0.5% to 5.0% by weight of the second layer.

24. The multilayer stretch film according to any one of claims 1 to 23, wherein the multilayer stretch film has an adhesion strength of at least 200 grams-force / inch as measured by ASTM D5458.

25. The multilayer stretch film according to any one of claims 1 to 24, wherein the multilayer stretch film has an adhesion between the second layer and the first layer in the range of 5 to 100 grams-force / inch, as measured by ASTM D5458.

26. The multilayer stretch film according to any one of claims 1 to 25, wherein the amount of graphene is in the range of 0.5% to 10% by weight of the core layer.

27. The multilayer stretch film according to any one of claims 1 to 25, wherein the amount of graphene is in the range of 1% to 10% by weight of the core layer.

28. The multilayer stretch film according to any one of claims 1 to 25, wherein the amount of graphene is in the range of 1% to 5% by weight of the core layer.

29. The multilayer stretch film according to any one of claims 1 to 28, wherein the core layer comprises a plurality of individual layers, each of which contains graphene in an amount ranging from 0.5% to 10% by weight.

30. The multilayer stretch film according to any one of claims 1 to 29, wherein the core layer further comprises a second polymer resin.

31. The multilayer stretch film according to claim 30, wherein the second polymer resin is a linear low-density polyethylene resin.

32. The multilayer stretch film according to any one of claims 1 to 31, wherein the core layer has a thickness of at least 70% of the total thickness of the multilayer stretch film.

33. The multilayer stretch film according to any one of claims 1 to 32, wherein the multilayer stretch film has a longitudinal tear strength of at least 700 g when measured according to ASTM D1922.

34. The multilayer stretch film according to any one of claims 1 to 33, wherein the multilayer stretch film has a tear strength of at least 1000 g in the tear direction when measured according to ASTM D1922.

35. The multilayer stretch film according to any one of claims 1 to 34, wherein the multilayer stretch film has an impact resistance of at least 450 g as measured by ASTM D1709.

36. The multilayer stretch film according to any one of claims 1 to 35, wherein the multilayer stretch film has a puncture resistance greater than 6 N when measured by ASTM F1306.

37. The multilayer stretch film according to any one of claims 1 to 36, wherein the first layer has a surface energy in the range of 25 mN / m to 30 mN / m.

38. The multilayer stretch film according to any one of claims 1 to 37, wherein the second layer has a surface energy in the range of 25 mN / m to 30 mN / m.

39. The aforementioned multilayer stretch film is 60 g / m 2 / day ~ 140g / m 2 A multilayer stretch film according to any one of claims 1 to 38, having a water vapor transmission rate in the range of / day.

40. The aforementioned multilayer stretch film, when measured according to ASTM D257-14, has a maximum size of 5.20 × 10 15 A multilayer stretch film according to any one of claims 1 to 39, having a surface resistivity of Ω / square.

41. The aforementioned multilayer stretch film measured according to ASTM D257-14 yielded 1.0 × 10⁻⁶. 17 Ω・cm ~ 2.0 × 10 17 A multilayer stretch film according to any one of claims 1 to 40, having a volume resistivity in the range of Ω·cm.

42. At least one first layer, each of which comprises a first polymer resin, At least one second layer, each of which comprises a polymer material, A core layer disposed between the at least one first layer and the at least one second layer, wherein the core layer includes graphene, and A multilayer stretch film including, A multilayer stretch film having a total of more than three layers.

43. The multilayer stretch film according to claim 42, wherein the total number of layers of the multilayer stretch film is 4 to 7.

44. The multilayer stretch film according to claim 42 or claim 43, wherein the amount of graphene is in the range of 0.5% to 10% by weight of the core layer.

45. The multilayer stretch film according to any one of claims 42 to 44, wherein the core layer comprises a plurality of individual layers, each of which contains graphene in an amount ranging from 0.5% to 10% by weight.

46. A first layer having a first surface and a second surface opposite to the first surface, wherein the first layer is a core layer containing graphene, A second layer disposed on the first surface of the first layer, wherein the second layer is a slip layer containing a first polymer resin. A multilayer stretch film including [this].

47. The multilayer stretch film according to claim 46, wherein the amount of graphene is in the range of 0.5% to 10% by weight of the first layer.

48. A first layer containing a first polymer resin, A second layer containing polymer material, A core layer disposed between the first layer and the second layer, wherein the core layer includes graphene, and An orientation stretch film comprising a material, having a thickness in the range of about 4 μm to about 10 μm.

49. The orientation stretch film according to claim 48, wherein the orientation stretch film is a stretched film obtained by stretching a multilayer stretch film such that the molecules in the film are oriented along the stretching direction.

50. The orientation stretch film according to claim 49, wherein the total thickness of the multilayer stretch film is in the range of about 14 μm to about 50 μm.

51. The orientation stretch film according to claim 48, wherein the first polymer resin in the first layer of the orientation stretch film is a low-density polyethylene resin or a linear low-density polyethylene resin.

52. The orientation stretch film according to claim 48 or claim 51, wherein the polymer material in the second layer of the orientation stretch film is a plastomer.

53. The orientation stretch film according to any one of claims 48 and 51 to 52, wherein the amount of graphene in the core layer of the orientation stretch film is in the range of 0.5% to 10% by weight of the core layer.

54. The orientation stretch film according to any one of claims 48 and 51 to 53, wherein the orientation stretch film has a stretch ratio in the range of about 1:1.5 to about 1:

4.

55. The orientation stretch film according to any one of claims 48 and 51 to 53, wherein the orientation stretch film has a stretch ratio in the range of about 1:1.5 to about 1:

3.

56. The orientation stretch film according to any one of claims 48 and 51 to 53, wherein the orientation stretch film has a stretch ratio of about 1:

2.

57. The orientation stretch film according to any one of claims 48 and 51 to 53, wherein the orientation stretch film has a stretch ratio of about 1:2.

5.

58. The orientation stretch film according to any one of claims 48 and 51 to 53, wherein the orientation stretch film has a stretch ratio of about 1:

3.

59. The orientation stretch film according to any one of claims 48 and 51 to 58, wherein the orientation stretch film is a biaxially orientation stretch film.

60. The orientation stretch film according to any one of claims 48 and 51 to 58, wherein the orientation stretch film is a mono-oriented or uniaxially oriented stretch film.

61. The multilayer stretch film according to any one of claims 48 and 51-60, wherein the oriented stretch film has an adhesion strength of at least 250 grams-force / inch as measured by ASTM D5458.

62. The multilayer stretch film according to any one of claims 48 and 51-61, wherein the oriented stretch film has an adhesion between the second layer and the first layer in the range of 50 to 100 grams-force / inch, as measured by ASTM D5458.

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